I would strongly advise you to learn how CSS Flexbox (or CSS Grid) works, it's easier to maintain, it will give you much more flexibility AND it will be responsive (if you give your blocks a fixed width in pixels, they will not be responsive).
Here's a link to get you started: https://www.w3schools.com/css/css3_flexbox.asp

The fact that an opinion is widely held is no evidence whatsoever that it is not utterly absurd.
Personal website: https://jaydot.nl

I have tried to update to Joomla 3.8. I downloaded Bitumi, but have not found a template similar to the one that I use.
At this time, I am trying to make a single page with 3 blocks in a row, inside a larger block. I have the page all set up, but cannot get 3 blocks in a row.

It's your website and (to put it bluntly) it's your problem, sorry. Although there is a forum category for "J! 1.0-related" discussions, people who continue to use J! 1.0 are living outside the rest of the community that has moved on. J! 1.0 ceased to be supported as of 22 July 2009. With literally millions of templates to choose from, saying that you "have not found a template similar to the one that I use" is more of an excuse than a reason to keep using what you're using.

As I say, it's your website but it's not really something most of us may be able (or willing) to assist you with. Good luck.

I agree with @Jaydot's advice.

https://www.kuneze.com/blogFormer member of Kunena project teamIf you think I’m wrong then say “I think you're wrong.” If you say “You’re wrong!”, how do you know?

Heavens, Joomla 1!! I picked up your question in the "new posts" feed, and I never noticed which forum you posted in. I completely agree with Sozzled, you really should upgrade.
However, I don't think the Joomla version should influence the CSS, unless you are also using an ancient browser (See Can I Use)?

So I couldn't say why you are seeing a column.
The following code works flawlessly for me...

I am working on the Joomla upgrade to 3.8.5. One reason that I haven't upgraded before is that the website is mature & well understood, and works with no glitches. That being said, I did a screen shot of the page with the 3 blocks in the debugger. I reduced the code to the simplest, just 3 blocks with the numbers 1, 2, and 3. What that indicates is that the text is inline. It appears the <style></style> is ignored.

Screen Shot.doc

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